Multi-photon and electron collisions

One of the major outstanding problems in atomic physics is the accurate calculation of collision data for low ionization stages of iron peak elements such as iron, cobalt and nickel.
This data is urgently required in the analysis of observations by the Hubble Space Telescope
of gaseous nebulae and in the analysis of laboratory spectra from, for example,
laser-plasma interactions and tokamaks.

It is now possible to include considerably more sophisticated wave functions
to describe both the target and the collisional states than was previously possible.
First calculations are showing detailed CI effects in electron collisions with atoms or
atomic ions with an open 3d shell.
This has revealed the need for extensive calculations to allow for correlation effects both
in the target and in the collision system

The PRMAT
codes scale well and are able to exploit the high-end computing resources available on HPCx.
They have been applied successfully in LS coupling to study electron collisions with FeII,
FeIII and FeIV, where comparison with previous work demonstrates the importance of including
additional correlation effects and coupled channels and the need for using a sufficiently
fine energy mesh. Typical results show complex resonance structures.